STRUCTURE OF MIDGUT AND PERITROPHIC MATRIX IN THE LAST INSTAR LARVAE OF CULEX PIPIENS (DIPTERA: CULICIDAE)

ABSTRACT Larval midgut and peritrophic matrix (PM) of Culex pipiens were investigated by light and electron microscope. Foregut and anterior midgut together form the special folding area called cardia. Cardia and gastric caeca are located in the thorax. Abdominal midgut follows the gastric caeca and lies between the first and the fifth abdominal segments. The luminal surfaces of the structures mentioned above are lined by single layered epithelial cells. However, the cell sizes and staining properties exhibit differences. The epithelial cells of the anterior midgut which are located in the cardia, produce PM. It surrounds the food bolus and lies to the end of the fifth abdominal segment. Golgi canals of midgut epithelial cells are upright to the apical membrane of the cell and the cellular organelles are seldom in peripheral cytoplasm. Electron-dense granular and electron-lucent microfibrillated layers are seen in the electron micrograph of PM. The thick microfibrillated layer is separated into three regions by electron dense bilayer Key Words: Midgut, Peritrophic matrix, Culex pipiens, Larva, Mosquito